Soundgarden is one hundred levels superior to Nirvana, as are Alice in Chains and Pearl Jam.

But take a mediocre guitarist with a godawfully annoying voice, detune & rearrange the More Than A Feeling riff and everybody eats it up.

I agree with you in terms of quality (except Pearl Jam), but taste is subjective so they have to go by more "objective" measures for this kind of thing, like album sales, radio play, how influential they were in the music scene.

Ultimately though, who cares? People make a huge deal when it comes to the Rock and roll hall of fame, grammys, and even other forms of awards like the Oscars and Emmys when something or someone they like doesn't get in over someone who they don't like. An award or recognition shouldn't change how you feel about a band. Sure it's sometimes nice to see a band you love get a pretty meaningless award like this, but I don't need the hall of fame to tell me that Alice in Chains is better than Nirvana.